from dotenv import load_dotenv
import jinja2
from jinja2.ext import Extension
from jinja2.lexer import Token
from markupsafe import Markup
import os
from pyramid.settings import asbool
import textwrap


def asbool_filter(value):
    return asbool(value)

def multiline_filter(value):
    # strip only the leading whitespaces from the first line
    value = value.strip(' ').strip('\n')
    if value:
        lines = textwrap.dedent(value).split('\n')
        return '\n    ' + '\n    '.join(lines)
    return ''

def ini_filter(value):
    if isinstance(value, Markup):
        return value
    if not isinstance(value, str):
        return value
    return value.replace('%', '%%')

class IniEverythingExtension(Extension):
    """
    Insert a `|ini` filter at the end of every variable substitution.

    This will ensure that all injected values are converted to INI.
    """
    def filter_stream(self, stream):
        # This is based on
        # https://github.com/indico/indico/blob/master/indico/web/flask/templating.py.
        for token in stream:
            if token.type == 'variable_end':
                yield Token(token.lineno, 'pipe', '|')
                yield Token(token.lineno, 'name', 'ini')
            yield token

def render_template(path, context):
    base, name = os.path.split(path)
    if not base:
        base = os.getcwd()
    env = jinja2.Environment(
        loader=jinja2.FileSystemLoader([base]),
        undefined=jinja2.StrictUndefined,
        extensions=[IniEverythingExtension],
    )
    env.filters['bool'] = asbool_filter
    env.filters['multiline'] = multiline_filter
    env.filters['ini'] = ini_filter

    template = env.get_template(name)
    return template.render(context)
    
def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument('--env')
    parser.add_argument('--env-file')
    parser.add_argument('--template', default='site.ini.in')
    parser.add_argument('-o', '--output-file', default='site.ini')

def main(cli, args):
    if args.env_file:
        load_dotenv(args.env_file)

    else:
        override = args.env or os.environ.get('DOTENV')
        for path in (
            f'.env.{override}.local' if override else None,
            f'.env.{override}' if override else None,
            '.env.local',
            '.env',
        ):
            if path and os.path.exists(path):
                load_dotenv(path)

    result = render_template(args.template, {
        'env': os.environ,
    })

    with open(args.output_file, 'w', encoding='utf8') as fp:
        fp.write(result.rstrip() + '\n')